ErikForwerk.MissingLinq 0.1.1

ErikForwerk.MissingLinq

What is MissingLinq?

MissingLinq is a lightweight .NET library that fills the gaps in LINQ by providing commonly needed extension methods that are not part of the standard System.Linq namespace.

The standard LINQ API covers a broad set of sequence operations, but experienced developers frequently find themselves writing the same small utility methods over and over again across projects. MissingLinq collects these recurring patterns into a single, well-tested, and NuGet-distributed library so you never have to reinvent them again.

Goals

• Complement LINQ — not replace it. Every method in this library feels like a natural addition to what System.Linq already offers.
• Zero friction — drop the NuGet package in and the extension methods are immediately available on IEnumerable<T>, arrays, and other collection types.
• Correctness first — every method ships with a full suite of unit tests and benchmarks to ensure both behaviour and performance are well understood.
• Modern .NET — the library targets .NET 10 and embraces current language features such as nullable reference types, collection expressions, and tuple return types.

Installation

dotnet add package ErikForwerk.MissingLinq

Available Extensions

Split

Splits a sequence into two groups in a single pass, based on a predicate — something LINQ's Where cannot do without enumerating the source twice.

int[] numbers = [1, 2, 3, 4, 5];

var (evens, odds) = numbers.Split(n => n % 2 == 0);
// evens → [2, 4]
// odds  → [1, 3, 5]

IsNullOrEmpty

A null-safe emptiness check that mirrors the familiar string.IsNullOrEmpty pattern for collections.

int[]? empty = null;
empty.IsNullOrEmpty(); // true

List<string> names = [];
names.IsNullOrEmpty(); // true

Join

Concatenates the elements of a string sequence into a single string — a direct counterpart to string.Join, but as a LINQ-style extension method available directly on IEnumerable<string>.

string[] words = ["Hello", "World", "foo"];

string result = words.Join(", ");
// result → "Hello, World, foo"

string csv = words.Join(',');
// csv → "Hello,World,foo"

Both overloads throw an ArgumentNullException if source (or the string separator) is null.

Project Structure

ErikForwerk.MissingLinq/
├── Source/
│   └── ErikForwerk.MissingLinq/             # Library source
├── UnitTests/
│   └── ErikForwerk.MissingLinq.Tests/       # xUnit test suite
└── Benchmarks/
    └── ErikForwerk.MissingLinq.Benchmark/   # BenchmarkDotNet benchmarks

Contributing

Contributions are welcome! If you regularly find yourself writing a LINQ-like helper that is absent from the standard library, feel free to open an issue or submit a pull request.

Please ensure all new methods are accompanied by:

• XML documentation comments
• Unit tests (using xUnit)
• A benchmark (using BenchmarkDotNet)

License

This project is licensed under the MIT License.